1. Field of the Invention
This invention relates to a motion pick-up for the production of electric timing signals at instances of time at which given points of a path of motion are crossed, and more particularly to such a pick-up in which the path of motion is crossed by a light beam in a non-mechanical printing system.
2. Description of the Prior Art
Motion pick-ups are required in many applications. An example of such an application is a non-mechanical printer, in which, for example, with the aid of a light beam, a charge image of the character which is to be printed is produced on a photoconductor drum. This character is developed and is then transferred to a web of paper in a transfer station, and is fixed upon the paper web. Generally, the charge images of a plurality of characters are produced next to one another in a line extending along the surface of a photo conductor drum parallel to the axis of rotation of the drum. To this end, the light beam must be deflected in the axial direction of the photo-conductor drum. Then, however, a character pulse train is required which indicates when the light beam must produce a charge image of a character on the photo conductor drum. That is to say, that whenever a character pulse occurs, the light beam is switched on and is conducted to the appropriate point of the photo-conductor drum.